Magnetic nanoparticles coated with aminated polymer brush as a novel material for effective removal of Pb(II) ions from aqueous environments

Environmental Science and Pollution Research - In the present study, a poly (vinylbenzyl chloride) grafted Fe3O4 nanoparticle (Fe3O4@PVBC) was prepared by surface-initiated reversible addition...     

Evaluating efforts to build sustainable WEEE reverse logistics network design: comparison of regulatory and non-regulatory approaches

Many developing countries such as Turkey are still making an effort on building an infrastructure for waste of electrical and electronic equipment (WEEE) reverse logistic network design (RLND) processes. It is obvious that policies/laws/regulations related to WEEE management provide a sustainable framework for implementation in the RLND. The question is here: Does the implementation of WEEE directives make sense in terms of reducing the total cost of the network in the long term? This study aims to compare regulatory and non-regulatory situations of WEEE RLND in developing countries by formulating two models named as ‘regulatory’ and ‘non-regulatory’. Model 1 is considered as sustainable with economic, environmental and social goals, and the quotas imposed by the environmental directive are taken into consideration as the data of product return amount. In Model 2, only economic goal is considered, and product return amount is forecasted using Artificial Neural Network (ANN). A case study is conducted in a recycling company in order to evaluate performance of the proposed models. This study contributes to the relevant literature by (1) comparing the regulatory and non-regulatory situations RL models explicitly and (2) proposing ANN model to forecast EEE product return or WEEE quantity for non-regulatory situation.     

t-BuOK catalyzed bio-oil production from woody biomass under sub-critical water conditions

The substitution of fossil fuels and fossil-based products with biofuels and biomass-based products is indispensable for a sustainable society and a green environment. The liquefaction of biomass to produce biofuels under sub- and/or super-critical water conditions is one of the most promising methods that might allow this substitution. Here, for the first time, we report the results of the liquefaction of woody biomass under sub-critical water conditions at 250, 300, and 350 °C using potassium tert-butoxide (t-BuOK) as a catalyst. To compare and evaluate the catalytic performance of t-BuOK, the experiments were also performed under identical conditions using KOH as the catalyst. The product distributions obtained using either KOH or t-BuOK as the catalyst were very similar. The total oil yields increased and the solid residue yields decreased when either KOH or t-BuOK were used at reaction temperatures of 300 and 350 °C. The total bio-oil yields obtained at 300 °C with t-BuOK and KOH were 41.9 weight (%) and 43.0 weight (%), respectively, whereas the total bio-oil yield from the thermal run at 300 °C was approximately 24.0 weight (%). Although the O/C ratio of the raw material is 0.70, the O/C ratios of the light and heavy bio-oils obtained from the KOH catalytic run are 0.38 and 0.25, respectively. In addition, the O/C ratios for the light and heavy oils obtained from the t-BuOK catalyst are 0.41 and 0.26, respectively. We estimate that the heating values of the light and heavy bio-oils obtained by either catalytic run (t-BuOK or KOH) are approximately 24 MJ kg^?1 and 29 MJ kg^?1, respectively     

Supercritical fluid extraction of biofuels from biomass

A sustainable source of energy production can be provided using renewable resources. For instance, biomass is transformed into biofuels using several techniques such as supercritical fluid extraction, an effective thermochemical process. Here we review results on biofuels obtained from lignocellulosic and algal biomass using supercritical fluids. Biofuel yield and composition are controlled by operating conditions such as extraction temperature, pressure, biomass and solvent type, and the presence of catalysts. The extraction temperature is the major factor controlling biofuel yield. Biofuel yields can also be improved with the use of catalysts. Major compounds in biofuels from lignocellulosic biomass are phenols, catechols, guaiacols, syringols, syringaldehydes, syringyl acetone, acids, and esters. Most of these compounds are produced by lignin decomposition in lignocellulose. Furfural and derivatives are produced by the decomposition of cellulose and hemicellulose. Fatty acid alkyl esters are formed from lignin fragmentation by condensation of compounds bearing C–O or C=O. Prominent compounds in biofuels from algal biomass are saturated or unsaturated fatty acid alkyl esters.     

Selection of renewable energy systems sites using the MaxEnt model in the Eastern Mediterranean region in Turkey

Environmental Science and Pollution Research - Global warming has become the center of worldwide environmental concerns, especially in recent years. One of the ways to deal with global warming that...     

Biogas production from olive pomace

Biogas production from a slurry obtained by mixing finely ground olive pomace in water was investigated using anaerobic digesters of 1-l working volume at 37°C. A start-up culture was obtained from a local landfill area and was adopted to the slurry within 10 days at this temperature. The biogas generation rates were determined by varying the total solids (TS) concentration in the slurry and the hydraulic retention time (HRT) during semi-continuous digestion. The maximum rate was found to be 0.70 l of biogas per l of digester volume per day, corresponding to a HRT of 20 days and 10% TS with a yield of 0.08 l biogas per g chemical oxygen demand (COD) added to the digester. The methane content of the biogas was in the range of 75–80% for both batch and semi-continuous runs, the remainder being principally carbon dioxide.     

Energy and emission benefits of chicken manure biogas production: a case study

Studies on the production of biogas of different organic materials in an anaerobic environment are being carried out all over the world. The most important parameters in these researches can be listed as raw material potential, production processes, economic analyses, and environmental effects. Chicken manure is one of the raw materials used in biogas production. In this study, in addition to the analysis of biogas and energy production potential from chicken manure, greenhouse gas emissions were analyzed to evaluate environmental effects. In Turkey, chicken manure is not adequately processed and causes environmental pollution. The model biogas plant and potential energy generation were researched in this field study. The pilot plant produces 8.58 million m³ of biogas per year by processing about 110 thousand tons of waste. It produces 17 GWh/year of electricity and 16 GWh/year of thermal energy, as well as reducing CO₂ greenhouse gas emissions by 13.86 thousand tons/year.